DTB Audio Player Refined in Second Round of User Tests
Practice makes perfect. To the National Library Service for the Blind and Physically Handicapped (NLS), Library of Congress, this makes perfect sense. That is why meticulous, ongoing evaluation is key to developing the digital talking-book machine (DTBM). NLS recently completed the second in a series of eight usability tests on the latest player model, an essential step toward finalizing requirements and design.
Four main goals guided these tests: validating user-interface design and defining priorities for basic and advanced players; defining patron understanding and use of primary DTBM features; gathering feedback on player design and specific physical features; and lastly, improving the design and development of the models to be tested in round three.
"With each round of testing, NLS gains a deeper understanding of user and librarian needs, which helps us further refine player capabilities and design," says Frank Kurt Cylke, NLS director. "Patron and librarian feedback is essential to building the best machine possible."
Sixty-nine current and potential patrons - with varied visual, physical, and cognitive impairments - participated in the study. Users ranged from children to seniors and were grouped by gender, age, and skill. Testing was facilitated by the National Federation of the Blind (NFB) in Baltimore and Cleveland and by the Trace Research and Development Center of the University of Wisconsin at Madison. Interviews with library staff also yielded valuable insight into the system's functionality.
"This series of usability tests was intended to see if engineers are getting the design right from the perspective of librarians and patrons," notes Michael Moodie, NLS deputy director. "From the results of these tests, we will be able to validate and refine some requirements and turn them into specifications for the machine."
For the first time, users conducted operational tasks on models of digital talking-book cartridges and players. The models incorporated ideas from initial user tests. While constructed of a special modeling foam, these models had functional buttons that were connected to actual digital talking-book recordings to simulate reading.
Operational tasks conducted on the player reflected typical usage scenarios. Testers examined the accessibility of basic functions, including primary and secondary controls and player features. All features needed to be obvious to patrons with varied capabilities and player experience.
The users appraised the shape, placement, tactile appeal, and ease of use of control buttons and the logic and clarity of navigation features. They assessed player size and appearance, cartridge insertion, power cord storage, and the use of the retractable handle and headphone jack.
NLS's top priority is producing a player that is both easy to use and navigation-friendly. "You can put in all the bells and whistles in the world, but if the user doesn't understand how to operate the machine it's worthless," emphasizes Michael Katzmann, head of the Engineering Section of NLS. "Player features must be obvious to users."
Librarians were interested primarily in maintenance issues such as cleaning players, re-labeling cartridges, stacking DTBMs for storage, and mailing-container handling. Librarians also desired a method for patrons to notify them of cartridge problems on return.
Testing does not stop with users. Engineers conduct their own field tests to ensure that the player meets NLS's high standards. The player must survive tough endurance exercises and still be functional. It must withstand a series of drops on all sides from as high as three feet, and resist scratches, spills, vermin, and extreme temperatures. Additional software-based testing evaluates its technical specifications.
According to Robert Fistick, acting chief, Materials Development Division, usability testing helps NLS pinpoint patron priorities so that the player is designed to meet their top needs. The findings reveal that patrons continue to value accessibility, usability, portability, and that easy maintenance continues to be the highest priority for librarians and repair personnel.
Users suggested improvements to audio instructions housed in the player. They also expressed preferences on handle positioning, cord storage compartment, and the cartridge mailing container.
Moodie stated that "All of these findings are significant because they will be evaluated and incorporated into the ongoing design and development process for the cartridge and player."
Based on the findings, engineers will explore several recommendations for improvement including changes to control layout, behavior, and complexity; cartridge insertion; and cord storage methods.
Survival Of the Fittest
Creating an optimal player is difficult. Engineers must negotiate many competing requirements before finalizing the design.
Conflicts often relate to portability and accessibility. For example, deciding between long-running batteries and portability is a big issue. Higher battery capacity involves increasing the size and weight of the player, which ultimately inhibits portability and increases cost. A sleek yet stackable player design is another challenge. A rounded top may be stylish but it is impractical for storage and handling. In this case, form should follow function.
NLS strives for a happy medium and makes trade-offs based on the best interests of patrons and librarians.